function hide(id)
{
	ID = document.getElementById(id);
	ID.style.display = "none";
}

function show(id)
{
	ID = document.getElementById(id);
	ID.style.display = "";
}

//
//				Function to show / hide a div.
//
function change(id)
{
	ID = document.getElementById(id);
	if(ID.style.display == "")
	{
		ID.style.display = "none";
	} else	{
		ID.style.display = "";
	}	
}

function notEmpty(object, defaultValue, required, error_report, mail_validation)
{

	// Define variables
	var success;
	var result;

	success = 'true';
	result	= success;

	// Get object
	var MyTextField = document.getElementById(object);

	switch(required)
	{

		case 'Y' :

			if( MyTextField.value != defaultValue )
			{

				if( MyTextField.value == '')
				{

					result = ' - het verplichte veld ' + defaultValue + ' is niet ingevuld';

				}else{

					// Check if field requires e-mail address validation
					if(mail_validation == 'Y')
					{	

						// Validate email address
						var reg = /^([A-Za-z0-9_\-\.])+\@([A-Za-z0-9_\-\.])+\.([A-Za-z]{2,4})$/;
						var address = MyTextField.value;

						if(reg.test(address) == false) {

							result = ' - het ingevulde e-mailadres is niet geldig.';

						}else{

							//No Action		
							
						}

					}else{

						//No Action
						
					}
					
				}

			}else{

				result 						= ' - het verplichte veld ' + defaultValue + ' is niet ingevuld';
				MyTextField.style.border 	= 'solid 1px red';
				MyTextField.style.color 	= 'red';	
			}

		break;

		case 'N' :

			if( MyTextField.value != defaultValue )
			{

				//No Action
				
			}else{

				MyTextField.value = '';
				
			}
			
		break;
	
	}

	if(result != 'true')
	{ 
		error_report = error_report + result + '\n'; 
	}

	return error_report;

}

function checkbox_check(object, error_report)
{

	result = document.getElementById(object).checked;

	switch(result)
	{

		case false :

			var MyCheckBox 			= document.getElementById(object);

			error_report 			= error_report + ' - Je bent nog niet akkoord gegaan de aanmelding \n';

			MyCheckBox.style.border	= 'solid 1px red';
			
		break;

		case true :

			// No Action

		break;
	}
	
	return error_report;

}

function send_request()
{

		var error_report;
		var error_report_intro = 'Bij het verzenden zijn de volgende problemen opgetreden \n\n';
		
		error_report = '';
		
		error_report = notEmpty("given", "voornaam", "Y", error_report, 'N');
		error_report = notEmpty("prefix", "tussenv.", "N", error_report, 'N');
		error_report = notEmpty("surname", "achternaam", "Y", error_report, 'N');
		error_report = notEmpty("school", "school", "N", error_report, 'N');
		error_report = notEmpty("class", "klas", "N", error_report, 'N');
		error_report = notEmpty("mail", "e-mail", "Y", error_report, 'Y');
		error_report = checkbox_check("optin", error_report);

		if(error_report != '')
		{

			alert(error_report_intro + error_report);

		}else{

			document.add_entry_form.submit();
			
		}

}


function clear_this(field, defaultValue)
{
	
	if(field.value == defaultValue)
	{

		field.value='';

	}else{

		// No Action
		
	}
	
}

function confirm_close(message, object) 
{

	var answer = confirm(message);
	
	if (answer)
	{

		hide(object);
		
	}else{

		//No Action

	}

}